Method and means for forming from and securing to thin wrapper webs a reinforced tear strip



Dec. 29, 1970 GAMBERlNl 3,551,245

METHOD AND MEANS FOR FORM FROM sEcuR TO THIN WRAPPER WEBS A R FORCED ARSTR Filed July 12, 1966 3 Sheets-Sheet l 1 N2 I E I INVENT OR 8 IGOFFREDO GAMBER/N/ 7 ATTORNEY G. GAMBERlNl Dec. 29, 1970 METHOD ANDMEANS FOR FORMING FROM AND SECURING TO THIN WRAPPER WEBS A REINFORCEDTEAR STRIP Filed July 12, 1966 3 Sheets-Sheet 2 INVENTOR GUFFREDOGAMBER/N/ ATTORNEY Dec. 29, 1970 GAMBERlNl 7 3,551,245

METHOD AND MEANS FOR FORMING FROM AND SECURING TO THIN WRAPPER WEBS AREINFORCED TEAR STRIP Filed July 12, 1.966 3 Sheets-$heet 3 I ndINVENTOR GOFFREDO GAMBER/N/ BY 7 7 M ATTORNEY United States Patent3,551,245 METHOD AND MEANS FOR FORMING FROM AND SECURING TO THIN WRAPPERWEBS A REINFORCED TEAR STRIP Gotrredo Gamberini, Bologna, Italy,assignor to American Machine & Foundry Company, a corporation of NewJersey Filed July 12, 1966, Ser. No. 564,578 Int. Cl. B32h 31/00 US. Cl.156-260 9 Claims ABSTRACT OF THE DISCLOSURE Method and apparatus forforming a cellulosic wrapper wherein at least two strips are cut from asubstantially endless wrapper, superimposed one on the other to form acomposite tear tape and joined to the wrapper along the longitudinalaxis.

This invention relates to the forming and securing of reinforced tearstrips to impervious webs, preferably of thin cellulosic material (suchas the material known under the registered trade name of cellophane)designed for wrapping packages or packets, such as cigarette packets,and aims to provide an improved method and means permitting of readilyforming from and securing to said wrapper web a reinforced tear stripi.e. a tear strip having a thickness and strength which are greater thanthose of the wrapper web.

According to one of the known methods, the narrow tear strip is fed froma separate reel and secured to the packet wrapper. Thismethod permits ofemploying tear strips of any thickness and strength, but it presents thedrawback that a separate bobbin for the strip must be provided, fromwhich the tear strip is to be secured onto the packet wrapper. Thismeans a duplication of the wrapping and cutting means and a complicationof the whole Wrapping apparatus.

According to another method, the tear strip is obtained from a movingweb of thin cellulosic material, having a width in excess of that neededfor wrapping the packets. Said tear strip is severed from the wrapperweb proper whereafter adhesive is applied to one face of said strip andthe severed strip is superposed in a predetermined position of the saidwrapper web, with the adhesive-coated face against the wrapper web andthen secured thereto, whereafter the said wrapper web and superimposedtear strip are severed transversely of their lengths. This methodpresents some advantages over the above-outlined prior method, butpresents the drawback that the tear strip has the same thickness as thewrapper web of thin cellulosic material. Usually however the tear stripthus produced is excessively thin and weak for guaranteeing a reliableand precise tear off of the packet wrapper made from the same cellulosicmaterial; much more, it happens sometimes that the same tear strip istorn before tearing the Whole wrapper.

In order to overcome this drawback, according to the invention means areprovided for forming and securing a reinforced tear strip by cutting,glueing or welding together and securing to the wrapper web at least twostrips cut from a margin of the said cellulosic wrapper, thus providinga reinforced tear strip having a thickness which is at least double ofthat of the wrapper web, so that the Patented Dec. 29, 1970 packetwrapper may be securely torn in the desired position, along the edges ofsaid reinforced tear strip.

As, in practice is desirable to render the reinforced tear strip readilyvisible on the wrapper, it is advisable to employ, for glueing togetherthe single strips, a colored adhesive. The same effect may be obtainedalso, without having recourse to colored adhesives, by employing webshaving a colored side margin. Anyway, if it is not required to renderthe Whole tear strip well visible, it is advisable to make at least thegrasping end of said strip of a different color than the wrapper web.The invention also provides means for coloring said grasping or tailends of the tear strips, so as to render same readily visible.

The above and other characteristic features of the invention will bebetter understood from the following specification, reference being hadto the accompanying drawings, in which the invention is particularlyshown as applied to an automatic cigarette packet-wrapping machine,although it is apparent to those skilled in the art that the same meansmay be employed also on other packaging and package-wrapping machines.

In the drawings:

FIG. 1 is a diagram of a packet-wrapping device provided with means forobtaining from a thin web a doublethickness tear strip and for securingsaid strip to the remaining wrapper web;

FIG. 2 shows in somewhat enlarged scale and in a diagrammaticalperspective view the machine for producing packet wrapper blanksprovided with a reinforced (or double-thickness) tear strip;

FIG. 3 is in still more enlarged scale two details of FIG. 2;

FIG. 4 shows a length of cellulosic web from which the packet wrapperand the reinforced tear strip are formed as well as the wrapper webafter cutting of two strips, securing of the reinforced tear strip tothe wrapper web and cutting from one end thereof a wrapper blank;

FIG. 5 is a perspective view like of another embodiment of a machinelike that shown in FIG. 2;

FIG. 6 shows in enlarged scale two details of FIG. 5, which correspondsto those shown in FIG. 3; and

FIG. 7 shows a length of cellulosic web and a wrapper blank like thoseas shown in FIG. 4, but onto the wrapper web.

With particular reference to FIGS. 1 to 4, N is the Web of thin, usuallycellulosic, wrapping material which is drawn from reel 7 and is led ontosupporting roller 9 where a pair of rotary disc knives 1 and 2 slit theweb longitudinally along two parallel lines, which are also parallel toone of its margins, by forming two equal narrow continuous strips S1 andS2 and leaving a Wrapper web proper N1. The strips S1 and S2 are ledseparately onto grooved leading rollers 10-11 and 12-13, respectivelyand are led onto a common grooved roller 14, where they are superposed.Anyway, prior to arriving onto roller 14, strip S1 is led into contactwith a wick 3 which absorbs a liquid adhesive (which may be also a websolvent) from tank 4 and applies same under said strip S1. Thus, whenthis strip comes into contact, in correspondence of roller 14, withstrip S2, the two strips come to be glued or welded together and form areinforced strip S. Before reaching the position on roller 14, strip S2is provided with preferably colored sections E at suitable intervals, incorrespondence of the outer or grasping end of the tear strip S. Thiscoloring of spaced strip sections may be performed by means of arevolving sector 6 to which the coloring substance is fed by means of aconventional feeding device 15.

The reinforced strip S is then led over rollers 16-17, and over anapplier of adhesive contained in tank 18, is subsequently passed in thegroove of grooved roller 29', which rolls slightly inside of the outeredge of wranoer web N1 led on roller 33, and fed from roller 32.

The web N1, after removal of the strips S1 and S2 in correspondence ofroller 9, is led over roller 30 and between rollers 31 and 32 where aU-shaped notch 19 is cut from punch 20 mounted on roller 31, the line ofnotches 19 coming to be substantially in correspondence of the tearstrip S.

The reinforced tear strip S coated with adhesive, by being brought intocontact with web N1 on roller 33 sticks to said web and the adhesion isimproved by compressing the strip S on web N1 by causing same to passbetween a supporting brush 21 and a heated plate 22. To this effect theweb N1 and overlying strip S are pulled by roller pair 34-35.

The U-shaped notches 19 on N1 and the colored sections E on strip S areequally spaced, and the various parts of the just-described device areso mounted that the strip grasping sections E come to be always incorrespondence of notches 19.

Past the roller pair 34-35 the wrapper web N1 with the tear strip Ssecured in proximity of one of its margins, pass first between a pair ofrollers 36-37 to one of which a rotary cutter 23 is so mounted as to cutat intervals the strip S in correspondence of the colored section Elying on the basis of the U-punching 19, as clearly shown in the lowerpart of FIGS. 2 and 4.

Then the wrapper web N1 and tear strip S pass between a pair of holdingrollers 3839 and past these rollers are subject to the action of arotary cutter 24 having a blade made of two spaced sections: A longersection for cutting the web N1 on one side (designed by the referencenumeral 27 in FIG. 4) and a very small cutter section for cutting thenarrow strip 127 on the opposite side of notch 19.

The resulting wrapper blank N2 has the exact dimensions which are neededfor completely wrapping the packets or packages to be wrapped, wherebythe tear strip S comes to lie just under the (tucked) top end, while thecolored tear strip section B glued on the projecting tongue L, FIG. 4serves as grasping member for the tear strip end E.

Whenever it is desired to render the whole strip S well visible, bycoloring same, in another embodiment a colored adhesive may be employedeither for glueing the strips S1 and S2 together before applying same towrapper web N1, or for glueing the double-thickness tear strip S to thewrapper web N1.

In an alternative embodiment, which has been shown in FIGS. 5, 6 and 7,the web N is provided with a colored margin NC having the width of oneor two tear strips S1- S2 of the embodiment as shown in FIGS. 2 to 4.

In FIGS. 5, 6 and 7 it is assumed that the colored margin NC has thewidth of one of the strips and when severed by means of the rotarycutter 1 form a colored strip S1C which is glued or welded to theadjoining usually transparent strip S2 and form together a reinforced ordouble-thickness colored tear strip SC which is secured onto the web N1as in the previous embodiment.

These two latter embodiments render the whole reinforced tear strip SCwell visible and, at the same time permit of simplifying the apparatusfor obtaining the wrapper blanks N2 provided with a colored tear stripSC by eliminating the unit indicated in FIGS. 1 and 2 by the referencenumerals and 6, which serves for coloring sections E of the strip S2 atpredetermined intervals.

Of course, the invention may undergo numerous changes, without departingfrom the basic principles thereof which consists in forming reinforcingtear strips by slitting at least two strips from a web edge and glueingsame together in superimposed relation before fastening same to theremaining web part, before forming a wrapper blank. Anyway, it may beremarked that, in the foregoing specification and appended claims,whenever an adhesive is mentioned, it will be understood that instead ofan adhesive, a solvent of the wrapper and/ or strip material may beemployed, which by dissolving part of the material, forms an adhesive.

I claim:

1. A method of obtaining from continuous webs of cellulosic wrappermaterial reinforced strips and of securing said strips to said wrapperwebs so as to form reinforced tear strips, said method consisting incutting from said continuous wrapper web a plurality of adjoiningparallel longitudinal strips, while still leaving a web of a width whichis sufiicient to wrap a packet thereinto; leading at least one of saidstrips onto an adhesive-applying device so as to coat one face thereofwith adhesive; leading said strip with its adhesive-coated face intocontact with another of said strips, so as to cause same to sticktogether by forming a composite reinforced strip; applying adhesive toone face of said reinforced strip, guiding said reinforced strip withits adhesive-coated face against the web and pressing said web andsuperimposed strip while moving same between heating means, until saidreinforced strips is firmly adhering to said web and may function astear strip when a section of said web forming a Wrapper blank is wrappedabout a packet.

2. A method according to claim 1, in which means are provided forcoloring said strip at intervals corresponding to about a web length ofone wrapper blank employed for wrapping a packet.

3. A method according to claim 1, in which the web is substantiallytransparent and the adhesive employed for making a reinforced compositestrip is colored.

4. A method according to claim 1, in which the web and strips aresubstantially transparent and the adhesive for securing the strip tosaid web is colored.

5. A method according to claim 1, in which one of the web edges fromwhich the strips are cut, has a colored margin.

6. A method according to claim 1, in which the web is cut into wrapperblanks transversally to its length and to the tear strip securedthereto, the out being made so as to leave a short projecting tongue onone of its end and a corresponding U-shaped notch on its opposite end.

7. Apparatus for forming wrapper blanks provided with a reinforced tearstrip, from a continuous web of thin cellulosic material, designed forwrapping packets and having a width in excess of the height of thepackets to be wrapped, and comprising a reel of web having a width ofthe wrapper blanks to be formed plus a margin whose width issubstantially equal to the width of two tear strips; means for slittingsaid margin and forming two parallel strips; means for coating at leastone side of one of said strips with a substance capable of imparting tosaid coated side an adhesive capacity; means for superposing to saidadhesive-coated strip side the other of said two strips, and forming asingle double-thickness strip; means for coating one side of saidreinforced strip with a substance capable of imparting to the saidcoated side an adhesive capacity; means for securing said reinforcedstrip longitudinally onto the web from which the said reinforcedstrip-forming strips were cut, said secured reinforced strip beingadapted to act as a reinforced tear strip and means for first notchingand then cutting said web and reinforced tear strip at predeterminedintervals, so as to form wrapper blanks provided with a projectingtongue in correspondence of one end of the Wrapper blank.

8. Apparatus according to claim 7, in which at least one of the stripsforming the said reinforced tear strip is colored.

5 6 9. Apparatus according to, claim 7, comprising means FOREIGN PATENTSfOl' coloring at intervals a part Of the tear strip. 222 37 7 1959Australia 15 260 References Cied DOUGLAS J. DRUMMOND, Primary ExaminerUNITED STATES PATENTS 5 1,776,353 9/1930 Dunbar et a1 156-264 2,331,06710/1943 Young 156260 15627l, 512, 265

3,272,673 9/1966 Focke 156-512

